The idea for this, I suspect, came from the runoffs tech stickers. They have a place to write in the weight, displacement and maybe track. The runoffs supps state they must be on the doors (or the engine cover of an open wheel car) and most guys put them up near the mirror. I've never seen one get rubbed there.

BTW, this will be a big time saver for the good folks running the scale. Not so much for IT or open wheel cars, but prod and GT car weights are harder for the guys and gals behind the scale table to figure out.